Aiko CTH3-115, CTH3-150, CTH3-80, CTH3-200 Analog Signal Modulating Thermostat P/N, MS/TP Wiring

SECTION 10: WIRING

10.4.3Analog Signal Modulating Thermostat (P/N 90425105)

Aprogrammable, 7-day programming, modulating thermostat can be installed to supply an analog (4- 20mA) or (2-10Vdc with 500 Ohm resistor) control signal to dictate the heater(s) firing rate. The thermostat shall energize the T24 and T25 (R and W) terminals. For thermostat wiring, See Page 49, Figure 29 and Page 50, Figure 30. Optional room sensors (P/N 10081520) and outdoor air sensors (P/N 10081521) are available.

Room temperature averaging networks can be created with up to nine room sensors (P/N 10081520). Refer to thermostat installation instructions for wiring.

10.4.4Analog Signal Modulating Thermostat with LonWorks® Communication (P/N 90425104)

If LonWorks® communication is required, a

modulating thermostat can be installed to supply an analog (4-20mA or 2-10Vdc) signal to control the heater(s) firing rate. For thermostat wiring, See Page 49, Figure 29 and Page 50, Figure 30. Optional room sensors (P/N 10081520) and outdoor air sensors (P/N 10081521) are available for this thermostat, as well.

The modulating thermostat with LonWorks® provides networking capability in a LonWorks® system. Communications port running at 78 kilobits per second (kbs), this thermostat can be configured to perform a variety of activities in which data is sent or received on the LonWorks®. Information that can be shared, viewed and modified with network includes:

•Current year, month, day, hour, minute, second.

•System Mode.

•Space Temperature

•Outdoor air temperature

•Current setpoint

•Occupied/Unoccupied schedule commands.

•Space Temperature

allow integral peer to peer BACnet® MS/TP LAN network communications with configurable baud rates and can easily integrate with a building automation system.

MS/TP Wiring

Connect the -A terminal in parallel with all other -A terminals on the network and the +B terminal in parallel with other +B terminals.

10.4.6Sequence of Operation for Modulating Thermostats

The thermostat will control the heater(s) firing rate based on the demand signal communicated from thermostat program taking into account space temperature. The thermostat will energize T25 (W) terminal. At high heat, a demand signal will turn the heater(s) on at maximum heater(s) firing rate. Once the room temperature gets close to the thermostat set point, then the thermostat program will slow the heater(s) firing rate down until the room temperature reaches the thermostat set point.

10.4.5Analog signal Modulating with BACnet® Programmable Thermostat (P/N 90425109).

If BACnet® communication is required, a BACnet® enabled modulating thermostat can be installed to supply an analog output (0-10VDC) signal control to dictate the heater(s) firing rate. For thermostat wiring, See Page 51, Figure 31.

This thermostat is a flexible wall-mounted stand- alone control with combined controller/sensor. Temperature sensing is standard with optional humidity and motion sensing. BACnet® connections

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